The invention relates to a safety valve having a valve seat and a biased sealing body.
With known safety valves, a sealing disc in the closed condition of the safety valve is pressed onto a valve seat with a certain holding force. If a pressure of a medium acting against the sealing disc exceeds a predefined limit pressure effecting a force upon the sealing disc, which is greater than the defined holding force, then the sealing disc is pressed away from the valve seat by the medium, and the medium can escape through the safety valve, until the pressure has reduced to such an extent that the force upon the sealing disc arising due to the pressure is smaller than the holding force, so that the sealing element bears against the valve seat again in a sealing manner.
If the pressure of the medium in the pressure region in the valve seat reaches a value which lies close to the limit pressure for opening the safety valve, then there exists the problem of holding the sealing disc on the valve seat in a completely sealing manner at this pressure. Contamination, for example, can settle on the valve seat, or the valve seat itself or the sealing disc can de-form slightly, in particular with a frequent lifting from the valve seat and pressing onto the valve seat, so that the sealing disc possibly no longer sealingly bears on the valve seat, even on reaching pressures in the pressure region which are lower than the defined limit pressure.